.pre-header{
    background: rgb(255, 255, 255);
    box-shadow: rgb(240 241 242) 0px 2px 8px;
    height: 64px;
    display: flex;
    -webkit-box-pack: center;
    justify-content: center;
    -webkit-box-align: center;
    align-items:center;
    position: sticky;
    z-index: 2;
    top: 0px;
}
.jumbotron{
    background: #1FCDB6;
    height: 200px;

}
.jumbotron_header{
    color: white;
    font-size: 50px;
    font-family: 'Open Sans', sans-serif;
}
.jumbotron_content{
    color: white;
    font-size: 15px;
    font-family: 'Open Sans', sans-serif;
}

body{
    background: #FBFCFF;
}
.directory{
    margin-top: 20px;
    box-sizing: border-box;
    position: relative;
}
.title{
    font-family: "PingFang SC";
    font-weight: 600; /*字体粗细*/
    font-size: 20px;/*字体尺寸*/
    line-height: 28px;
    color: rgb(34, 34, 34);
}

.item{
    font-family: "PingFang SC";
    font-size: 16px;
    line-height: 19px;
    color: rgb(34, 34, 34);
    position: relative;
    margin-top: 16px;
    
}
.item a{
    color: #000;

}
.item a:hover{
    color: rgb(31, 205, 182);
    cursor: pointer;
}
.box{
    position: fixed;
    top: 200px;
    right: 200px;
    background: rgb(255, 255, 255);
    box-sizing: border-box;
    padding: 30px;
    border-radius: 6px;
}

.main{
    background: white;
}
.level1{
    padding-left: 20px;
    font-family: "PingFang SC";
    font-weight: 600;
    font-size: 26px;
    line-height: 36px;
    position: relative;
    margin: 30px 0px 24px;
}
.level2{
    padding-left: 17px;
    position: relative;
    font-family: 'Open Sans', sans-serif;
    font-size: 16px;
    line-height: 1.62;
    text-align: justify;
    color: rgb(34, 34, 34);
}